Temperature-dependent CO<sub>2</sub> sorption and thermal-reduction without reactant gases on BaTiO<sub>3</sub> nanocatalysts at low temperatures in the range of 300?1000 K
Temperature-dependent CO<sub>2</sub> sorption and thermal-reduction without reactant gases on BaTiO<sub>3</sub> nanocatalysts at low temperatures in the range of 300?1000 K
复制标题
BaTiO<sub>3</sub> 纳米催化剂在 300?1000 K 低温范围内实现温度依赖性 CO<sub>2</sub> 吸附和热还原，无需反应气体
DOI：
10.1039/d2nr00883a
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发表时间：
2022
期刊：
影响因子：
6.7
通讯作者：
Ohba Tomonori
中科院分区：
文献类型：
--
作者：
Watanabe Takumi;Ohba Tomonori
减缓全球变暖的碳利用技术是环境科学的一个重要领域。CO2减排是碳利用的重要一步。然而，在减少能源消耗的同时减少二氧化碳排放面临着重大挑战。在这项研究中，CO2的热还原证明使用纳米催化剂在低于1000 K的温度下，并在300-1000 K的温度范围内的CO2吸附和还原机制进行了评估。在晶粒尺寸为7.4 ± 0.4nm的纳米催化剂（10 nm纳米催化剂）上的物理吸附主要发生在300 K，超过该温度后吸附量显著降低。CO2化学吸附发生在450 K以上，随后的CO2还原发生在500 K以上，这是基于程序升温反应所预期的。CO2还原降低900 K以上的10-nm的纳米催化剂，由于其晶体生长的失活。透射电子显微镜图像还表明，在600和800 K下，CO2完全还原成碳产物。因此，在500-800 K温度范围内，CO2还原的最佳条件为：该高活性热催化剂即使在极低的温度（500 K）下也实现了在没有任何还原剂的情况下将CO2还原成CO和碳产物。总之，在10 nm纳米催化剂上观察到温度依赖性的CO2吸附和还原; CO2物理吸附在300-500 K，CO2化学吸附在450 K以上，CO2还原在500-850 K，CO2和CO释放在800 K以上。
Carbon utilization techniques to mitigate the impact on global warming are an important field in environmental science. CO2 reduction is a significant step for carbon utilization. However, CO2 reduction with less energy consumption has major challenges. In this study, CO2 thermal reduction was demonstrated using nanocatalysts at temperatures lower than 1000 K, and the CO2 sorption and reduction mechanisms within the temperature range of 300–1000 K were evaluated. The physical adsorption on nanocatalysts with a crystal size of 7.4 ± 0.4 nm (10 nm-nanocatalysts) majorly occurred at 300 K and was considerably decreased beyond that temperature. CO2 chemisorption occurred above 450 K and subsequent CO2 reduction occurred above 500 K, which was expected based on the temperature-programmed reaction. CO2 reduction decreased above 900 K by the deactivation of the 10-nm nanocatalyst as a result of its crystal growth. The transmission electron microscopy images also indicated the complete reduction of CO2 into carbon products at 600 and 800 K. Therefore, an optimal condition of CO2 reduction in the temperature range of 500–800 K. The highly active thermocatalyst achieved CO2 reduction into CO and carbon products without any reducing agents even at an extremely low temperature (500 K). In summary, temperature-dependent CO2 sorption and reduction were observed on the 10-nm nanocatalyst; CO2 physical adsorption at 300–500 K, CO2 chemisorption above 450 K, CO2 reduction at 500–850 K, and CO2 and CO releases above 800 K.